Searched all over the place but cannot find anything similar. Here's the issue...

The setup:

- 'Page' content type
- 'Block Content' paragraph type

The 'Page' content type has a field for referencing the 'Block Content' paragraph, called "Components" (set to unlimited). Now we can use paragraphs within our page. Simple.

The 'Block Content' paragraph type has a field for referencing blocks (using the module [Block Field][1]). It also has two other fields for title and subtitle. These fields need to be displayed on the referenced block template for this paragraph instance. This is the issue.

I have included some images to show the setup.

I am trying to use theme_preprocess_block to inject these fields (title and subtitle) into the correct block using $vars['plugin_id'] from the block preprocess but the issue is that the block does not know its paragraph parent. And if I don't know the parent, I can't retrieve these fields that I need to inject into the block.

This [answer][2] suggests using the following to get the parent:

    $parent   = $variables['elements']['#node']->_referringItem->getEntity();

But in my case I could not find anything equivalent in my block preprocess function.

**Update 1:**
I tried (from within theme_preprocess_block):

    dpm($vars['elements']['content']['#block_content']->_referringItem->getEntity());
This give the following error:

    Error: Call to a member function getEntity() on null in limit_preprocess_block__banner_block()

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**IMAGE 1:**

[![enter image description here][3]][3]

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**IMAGE 2:**

[![enter image description here][4]][4]

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**IMAGE 3:**

[![enter image description here][5]][5]

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**IMAGE 4:**

[![enter image description here][6]][6]

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**IMAGE 5:**

[![enter image description here][7]][7]


  [1]: https://www.drupal.org/project/block_field
  [2]: https://drupal.stackexchange.com/a/246516/99337
  [3]: https://i.sstatic.net/Lb3lI.png
  [4]: https://i.sstatic.net/EWSWQ.png
  [5]: https://i.sstatic.net/9G4o5.png
  [6]: https://i.sstatic.net/hyi6t.png
  [7]: https://i.sstatic.net/km76J.png